This story was originally published December 02, 2002
A female biologist shows up in a remote Western town, battered and partly clothed.
A dentist's wife dies unexpectedly.
An infant girl succumbs after a long, mysterious illness.
In each of these baffling cases, police turned to scientific detectives at a Montgomery County laboratory for help. And each time, the scientists, much like their fictional counterparts on television's CSI, used high-tech instruments and old-fashioned ratiocination to help crack the case.
"Our lab is known for doing things most labs won't do or can't do," said Robert Middleberg of National Medical Services in Willow Grove.
Sometimes, he said, he and his colleagues are faced with specimens they don't recognize – strange blobs of goo packed in bags or jars. "That's not unusual . . . especially if a body was dismembered," he said, as if this only added to the allure of his job. It's a fascinating line of work, he said, and the most fascinating case so far was the one last summer, involving the biologist.
It began in 1997, when the biologist came running into the town of Reserve, N.M., partly clothed, bleeding and disoriented. She was taken to the hospital, where she slipped in and out of consciousness for several days.
Before she showed up in town, the woman had worked for several weeks with a fellow biologist, Patrick Ryan, tracking bears in the nearby forest. Her symptoms and her story made FBI agents suspect that her colleague had raped her after sneaking bear tranquilizer into her drinks or food.
It's the kind of crime that was once almost impossible to prosecute. From ancient times until the early 20th century, criminals had the upper hand when it came to poisoning or drugging, said Marina Stajic, director of forensic toxicology for the New York City medical examiner's office.
"The poisoning business really boomed in the Renaissance," she said, citing that period's advances in making poisons and lack of progress in detecting them.
It was only 70 years ago that authorities used chemical analysis for the first time to catch a poisoner – a woman who used arsenic to kill her husband. Now, every year it becomes harder to avoid getting caught as forensic scientists acquire increasingly powerful tools.
Currently, Middleberg's lab can detect the presence of more than 30,000 substances, most of them in very minute quantities.
But, in the rape investigation in New Mexico, police were hampered by the fact that by the time the investigation started, most of the tranquilizer would have left the victim's body. The only hope was to find the substance in hair, which retains very small amounts of foreign chemicals – traces smaller than a part per billion.
Middleberg, who testified at Ryan's trial, said he watched videotape the FBI had seized from Ryan, which showed him having sex with the victim while she appeared to be in a catatonic state.
Her symptoms displayed on the tape looked like the effects of the tranquilizer that the biologists carried to subdue bears, he said. But investigators would need to detect it in her hair to prove their case.
It wasn't until spring of this year that the lab was able to use a powerful enough instrument, called a time-of-flight mass spectrometer, to detect the drug. The machine worked the same way as the mass spectrometer they had depended on until that time, but it would give a more precise identification on a smaller sample.
The time-of-flight instrument was good enough to find that the bear tranquilizer had, indeed, been stored in the woman's hair. Ryan was convicted in July of rape, aggravated assault and kidnapping.
Even isolating a substance often isn't enough to prove guilt or innocence, because there are different ways foreign chemicals can get into someone's system.
A particularly confusing case came along in 1991, when an Upper Dublin dentist was accused of killing his wife.
At 52, she was found dead in a lounge chair, with no evidence of having suffered a serious illness.
Police became suspicious of her husband, William Phillips. "The police thought, if he was a dentist, how would he kill her? Maybe with an injection into the mouth? " Middleberg said.
What he found in the dead woman's mouth was a substance called papaverine, which could have been used as a poison. But it turned out to also be the same substance used during organ donation, to strip blood vessels from tissue. The wife had donated her organs, and papaverine had been used.
Phillips was acquitted in 1994.
In other cases, Middleberg is called on to assess whether a lethal substance in a person's body was the result of murder, or accident, or environmental exposure. In 1991, he was brought in on the case of Andrea Wanzie, a 7-month-old central Pennsylvania girl who died after being hospitalized more than 20 times for ailments ranging from dehydration to seizures.
A brother who was a year and a half older also was in and out of hospitals with mysterious maladies.
Andrea died of an upper respiratory infection that progressed to kidney failure. The baffled doctor began to suspect something was amiss.
The pattern of the girl's fatal illness – respiratory trouble followed by kidney failure – fit heavy-metal poisoning, Middleberg said. So he began testing for etals and found that the infant had a heavy concentration of mercury in her body — enough that he suspected she had been repeatedly exposed.
To confirm the presence of something like mercury, he said, forensic toxicologists use an instrument called an atomic absorption spectrophotometer. The instrument vaporizes metal atoms in a sample and shines light into them. It picks up the presence of specific atoms by the telltale way each one alters the wavelengths of light.
The girl's mother, Patti Wanzie, 26, maintained there must have been mercury contamination in her house. It wasn't impossible that the mercury could have come from environmental contamination, Middleberg said. So he had everyone else in the house tested. All were negative.
Police later acknowledged they had found a jar labeled "mercury" in the Wanzie house but had not confiscated it. When investigators returned to the house, the jar was gone. Still, faced with the lab's findings, the mother pleaded guilty to third-degree murder and was sentenced to 5 to 10 years in state prison. The judge concluded that Patti Wanzie suffered from a rare and controversial mental illness known as Munchausen syndrome by proxy, in which people try to get attention by making their children sick.
Middleberg said his job satisfaction comes not from catching bad people, but from doing good science.
"Some people have that mind-set – that they're trying to get someone," he said. "It shouldn't be that way – we're supposed to be objective scientists. " The satisfaction, he said, comes from the challenge of getting the right answer.